Hydraulic machine



w. M. WHITE HYDRAULIC MACHINE Filed Sept. 2, 1930 March 7, 1933.

, An 4object'of'the invention is toprovide a- 1115 from a reading of thespeciication and of the f of lines 1li-T11; III--III, Vand IVIV, and

in theplanes-of linesy correspondingxto the Patented Mar. 7, 1933 f a Appncation; mea ,september .2, 1930. if .semi ,Nm 479,226.

Thisinvention relate-s in.- generalto the art of. hydraulic machines and relatesmore spe,A

cilically to improvements in the construction .of hydraulic turbines.

hydraulic turbine-which isf/simple in construction andeflicientin operation. Another. object of the invention is-to provide `an improvementin the lconstruction .of the vanes "lq'mounted inthe spiral casing ofthe Francis type of hydraulic turbine, whiehwill effect an efficient deliveryfof-.theworking fluid'to f the turbine. Other ,objectsv and advantages of the present invention will become apparent drawing `forming a part-thereof.

Fig. 1- is a fragmentary central vertical section'through a hydraulic turbineinstallation embodying features ofthe invention.

2 Fig. Qis a fragmentary plan view to .an enlarged scaleillustrating the general arrangement of thev adjustableguide,vanes and the 1 stationary vanes, the' latter being'- shown in? 1 -central Vhorizontal section taken on line 5225s II-IL of Figure 1 and' further shows `one vof i the radial lines Rpassing through the axis of 'the `turbine shaft and points inlthev entrancey edge of a stationary vane 9 to indicate the enl trance' angles a, l), and c.

Fig. 3 is a sectional view of. a'stationary vane shown'inl Fig. Qtalzen on line .III-#III of Fig. 1, and indicates the entrance angle Z1' 1 in the-planeof thesection. Y

yFigc-4 is asectional viewof alstationary vane shown in Fig. 2 taken on line IV-IV of Fig. 1, `and indicates-the: entrance angle c in :the plane-of the section.

' Fig. 5 is a view similar to'Fig. 2zshowing 'y 40- a modified form of stationary. vanes, the same being` `shown in' central horizontal sectionr taken on line II-II, ofFigure 1 and similarly shows one of the radial'lines4 R passing through the vaxis, of the turbine shaft and points in thefentrance edge of a .stationary .vane- 19 toindicate the ent-rance angles a', and c. y y

Fig. -6 is a across-sectional view of the modified form ofstationary vane shown in kgal force :exerted by the water.

Fig.. 1, and indicates the entrance anglewb-v in the plane of the section. y

Fig. 7 is a cross-sectional view of thek modilied form of-vstationary vane shownin Fig. 5

taken on aline ysuch asIV-IV of Fig. .1, 55

and,- 'indicatesj the entrance. angle` cv in the plane of thesection. Y

Y Figure Sis a perspective View, lookingin the direction of the arrow of Figure 5,. of this modified. .form of stationary vane, the .60 upper end beingsevered from the speed .ring 81 along its t inner surface, and the. closed circuit dottedv lines v-b'eingdrawn in the vane body to facilitate/picturing...the cross section of the modified vane 19 iin the planes 55 latter two lines, below.the1line `II-.II.

In 'order that .this vinvention' may readily be understood the principle thereoff'will here .70

-be explained. Stationary vanes; orjspeed` vanes` are used lwithrspiral casings. The

functionof these vanes is to properly guide the hydraulicfluid and therefore these yvanes should be designedto conform to ytheflow-- of the. fluid `in the spiral casing in order that` maximum efficiency .of delivery may be realized. The. fluid entersthe spiral casing through-acylindrical conduit. It isl well known that water flowing through a cylin drical conduit has a much higher velocity at the center than at thewalls of the conduit,

so that` whenthe water is delivered to the spiral casing, that.v filament-of stream line of the water at the center of the supply conduit and which is. directedto flow around in the center of the spiral casingv does not maintain Aits relative. position `with .reference to the radius oficurvature of the Alongitudinal center of the spiral casing,` on account of vthe varying pressure produc-ed by centrifu- The amount of the pressure due to .centrifugal forceV is a function ofthe velocity of the: filament and the radius of curvature of thev arc on which the lchange yof direction takes place. Let us yassume a plane of measurable thickness, curvedin shape Aand, passing vertically and at right angles. to the plane of the spiralV casing through the longitudinal cen- .1Q

ter thereof. If now we consider a filament of water passing alongthe middle of said plane and one passing in the same plane, but near the wall of the spiral casing, it will be see-n that the difference in pressure from the inner side to the outer side of that filament of water at the middle of the plane will be considerably greater than the difference in pressure between the same two sides of that filament of water next the wall of the spiral casing on account of the din'erence in velocities of the two laments. Since these filaments lie in the same radius of curvature, the center filament having high velocity will flow away from th-e center of curvature of the spiral casing and the filament at the side, having low velocity will be forced toward or nearer to the center of curvature of the spiral casing. In other words the high velocity water in the spiral casing tends to turn on a large radius of curvature while the low velocity water adjacent the wall tends to turn on a short radius of curvature.

The flow of water in a spiral casing therefore consists of the low velocity water peeling 01T from the high velocity water like peeling` the skin of a banana from the center. But this means that the low velocity water turns on a short radius of curvature, which means that the direction of flow of this low velocity water is more nearly radial than the direction of flow of the high velocity water which finally passes the speed vanes along the center thereof.

' 'Ihis invention therefore consists essentially in the convexing of the entrance edge of longitudinally warped stationary or speed vanes to provide vanes having side guiding surface portions at the top and at the bottom, which are directed dierently from the guiding` surface portion at the center of the vanes to properly accommodate the different directions of flow at these points.' The preferred form is that in which the guiding surface portions adjacent the entrance edge at the top and bottom of the vanes are more nearly radially directed and the guiding surface portion adjacent the entrance edge at the center of the vanes is more nearly tangentially or nearly perpendicularly directed with reference, respectively, to radial lines passing through the entrance edgeof the vane at said portions and through the axis of the turbine shaft, as illustrated by the modification shown in Figs. 5, 6, 7 and 8.

I-Iaving now explained the principle une derlying this invention, the structures` with which it is contemplated to apply that prin ciple will now be described in detail.

Referring to Fig. 1, reference numeral4represents the spiral casing of a Francis type of hydraulic turbine. rl`his'casing is shown as partially formed by the usual speed ring 8 with which the novel stationary or speed vanes 9 forming the basis of this application are shown integrally formed. As far as this invention is concerned it is not essential that the spiral casing be formed or outlined in part by a speed ring as long as the curvature of the spiral casing be continued to points adjacent the guide casing. The guide casing consists of a top 6 and a bottom 13 shown surrounded by speed ring 8 and provides an annular fluid admission space between the runner 2 and the speed ring 8 forming the annular bell-shaped mouth or fluid exit portion of the spiral casing 4. In this annular space an annular series of adjustable guide vanes 3 having pivots 10 operatively connectedwith links 11 of adjusting mechanism is positioned. Reference numeral 5 indicates the usual draft tube below the runner 2, and

7 the shaft to which the runner 2 is lixed for rotation. Reference numeral 12 represents the particular convex outer orv entrance edge of the stationary vanes which is the same in both of the two modifications more fully disclosed by Figs. 2, 3 and 4 and Figs.,

5, 62 7, and 8, respectively. In other words the two modified forms of stationary vanes are the same in side elevation and as disclosed in Fig. 1.

Now referring to Fig. 2 it will be observed that the vanes l9 are rather flat in crosssec` tion although provided with slightly concave and convex opposed side faces. In

other words they are slightly warped longitudinally. By entrance angle is'meant the angle formed at a point in the entrance edge of the stationary vane by one of the substantially parallel, opposed guiding surfaces of the vane, meeting in said edge, and a radial line R passing through said point andthe ,A

progressive variation of the entrance angles a, o, c of the vanes 9 is due entirely to the form of the entrance edge 12 of the vanes 9 and the uniform warped conformation of these vanes as is readily apparent. This form of vane does give a satisfactory ventrance angle at the center of the vane being approximately 74 and therefore at this point provides a nearly tangential guiding surface which has been shown above to be the desired direction but has a relatively large entrance angle adjacent the top and bottom of the vane where the guiding surfaces should be nearly radial and therefore the entrance angle small as explained above.

The preferred form of the invention disclosed in Figs. 5, 6, 7 and 8 conforms more closely to the desired specications. In this modification the central angle a of the vane 19 is approximately 601/2". This is in contrast with the entrance angle b of Fig. 65 which is a section on a line such as III--III of Fig. 1, of approximately 67 and the entrance angle c of Fig. 7 which is a section on a line such as IV-IV of Fig. 1, of approximately 91/2". The guiding surface 10 forming with a radial line R the central entrance angle a is therefore nearly tangential or nearly perpendicular to the radial line R passing through the axis of the shaft 7 of the runner 2, and the guiding surfaces forming with other radial lines R entrance angles c adjacent the top and bottom of the vane are nearly radial, as desired. This-is accomplished by providing each vane 19 which is relatively thin as compared to their 20 width, as is the case in the vanes 9 of the modification shown in Figs. 2, 3 and 4, with a pair of longitudinal or lengthwise warps and providing the outer or entrance edge of each vane with a convex curvature 12 as in the prior modification. The forward warp or warp adjacent the entrance edge of the vane it will be noted increases in magnitude from the central horizontal portion of the vane toward its top and bottom, to provide nearly radial guiding surfaces adjacent the top and the bottom of the vane while the contiguous warp adjacent the exit or inner edge of the vane is constant as illustrated by Figs. 5, 6, 7 and 8. l

It will thus be seen that each of the two modifications of stationary vanes disclosed herein provides efficient means for guiding the hydraulic fluid through the annular bell shaped mouth or fluid exit portion, customarily formed by the usual speed ring of a spiral casing of a hydraulic turbine. But it will be noted that as far as this invention is concerned the presence or absence of a speed ring is immaterial as long as the general interior outline of the shown speed ring 8 forming a part of spiral casing 4 is maintained so that the disclosed stationary vanes may be mounted in the disclosed manner in such an annular mouth or fluid-passing-annular inner portion of a spiral casing by any means as for instance by bolts to the concrete foundation directly or by any other suitable means.

Reference is further made to Fig. 1 wherein it will be noted that the water discharges downward from the runner. In the operation of such types of turbines as illustrated in Fig. 1, it is common knowledge that the water flows more rapidly through the lower Y portion of the movable guide vanes 3 than it does through the upper portion of them and in consequence, more water will be drawn from that side of the spiral casing next to the discharge of the runner than from that i side of the spiral next to the top of the runner; lfIrr-'otherfworda byreference Sto; .1, ithe'flow 'radially' and actually kquantitatively y"along the'flow line fl willtbe more-than 'along the v:flow and sectioniline IIT-IV. 1

"l AInf-the:description-above` given, for -simp'lic-li 70 ity of explanation we have confined ourrethe vane is Ywarpedgsymmetricallyonf each sideofthe center -linejI-I-f-II, Fig. 1, but as a further improvement applicant proposes'75 to make that portion of the speed vane along the flow line f more radial than that portion of the vane along the flow section IV to accommodate the direction of the different quantities of flows of water at these two'80 points. vApplicant does not confine himself, therefore, to vanes warped symmetrically from the center line II-II but unsymmetrically as may be required to properly meet and guide the inflowing water.

It should be understood that it is not desired to limit the invention to the exact details of construction and operation herein shown and described, for various modifications may occur to persons skilled inthe art."90

It is claimed and desired to secure by Letters Patent: v

1. In a hydraulic machine, a spiral fluid conducting casing having an annular fluid exit portion and a plurality of vanes mount-*395 ed in said fluid exit portion, the entrance angles of which vary progressively from the top and bottom to a point intermediate the top and the bottom.

2. In a hydraulic machine, a spiral fluidllloo conducting casing having a fluid passing-annular inner portion, a plurality of vanes mounted in said fluid passing portion, each of said vanes having a plurality of longitudinal warps one of which is uniform through-1105 out the length of the vanes and the other of which is variable, and each of said vanes having a convex edge facing the interior of said casing.

3. In a hydraulic machine, a spiral fluid-V conducting casing having a fluid-passing annular inner portion, a plurality of vanes mounted in said fluid-passing portion, each of said vanes having a plurality of contiguous warps one of which increases in magni-d tude toward the top and bottom of each vane and each of said vanes being further provided with a convex edge adjacent said warp of increasing magnitude.

4. In a hydraulic machine, a spiral fluidi 3120 conducting casing having an annular bell shaped fiuid exit portion and means in said fluid exit portion providing nearly radial guiding surfaces for fluid adjacent the walls of said portion and nearly tangential guiding surfaces for the fluid adjacent the longitudinal center of said casing. f

5. In a hydraulic machine, a spiral fluid conducting casing having a fluidpassing-annular inner portion, and means in said fluid:l i

passing portion providing nearly radial guiding surface portions for the Huid adjacent the Walls of said portion and nearly tangential guiding surface portions for the fluid adjacent the longitudinal center of said casing.

In testimony whereof, the signature of the inventor is affixed hereto.

WILLIAM M. WHITE.

CERTIFICATE 0F CGRRECHN.

Patent No. 1,9%, 141i. Marcil 7, i933.

WILLIAM M. WHITE.

it is hereby certified that error appears in the printed specification et the above numbered patent requiring correction as follows: Page 3, lilies iiii and w3, ciaim 2, for the words "fluid passing" read "tiuidpassing"; and iiiie iii, ciaim 3, for "fluid-passing am" read "tiuid-passing-an-"; and that the said Letters Pat-eilt should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of May, A. D. i933.

M. J. Moore. (Seal) Acting Commissioner of Patents. 

